Over the past 25 years, semiconductor test technology requirements have been driven primarily by relentlessly increasing performance and transistor counts. A fundamental shift is underway driven by the emergence of new market demands (for example, mobility, security, ease of use, ease of system management, low power, etc.). This in turn is fueling the integration of different semiconductor technologies in more ways and in a greater set of applications than ever before. This in itself is a huge challenge to test as it is ultimately the application requirements or specifications that determine test technology requirements, but it would be impossible to capture a comprehensive set of applications and their associated test requirements trends within this chapter. Therefore, core semiconductor technology building blocks have been identified to provide a framework for describing the test challenges and trends associated with each core technology as well as for describing the test challenges associated with integrating these core technologies together either as a SoC or a SiP.
Each core semiconductor technology has certain applications associated with it and some of these will be used as a basis for extracting long-term trends. In particular, the ITRS publishes key technology attribute trends for CPU, ASIC, DRAM, and Flash memory. These will be referenced where appropriate in the core technology sections. Figure TST11 shows the core semiconductor technologies addressed in this chapter as well as examples of associated applications. The application mapping is intentionally loose as many of the examples listed may contain multiple core technologies. The core technologies are differentiated mainly by their inherent functional differences and thus their different test requirements. Two emerging core technologies that are not included in this revision are MEMS and optical.
- Organization of Cores for System Integration and Applications
In the recent past, these core semiconductor technologies and applications have demanded distinctly different test solutions, each having specific test equipment and interface tooling markets. Increasing integration is blurring these boundaries. It has also raised the stakes for DFT as successful integration is determined not just by “can it be done?” but also “can the integrated whole be tested economically?” The remainder of the Test Technology Requirements section will address the test challenges associated with increasing integration followed by the test requirements of each constituent core technology.